1. Field of Use
This invention relates generally to telescopic booms such as are used on mobile cranes or the like. In particular, it relates to the construction of telescopic boom sections for such telescopic booms.
2. Description of the Prior Art
Current practices in the construction industry and building trades require mobile cranes having telescopic booms which can handle increasingly heavier loads and raise them to greater heights. Attempts to increase boom size, load-handling capability, and strength merely by enlarging the size of prior art designs have not been entirely successful. As the physical size of such telescopic booms and the boom sections used therein are increased, and as the lengths to which they can be extended are increased, the booms become extremely heavy and awkward to operate. Further, the excessive deflections due to higher forces hinder precise load handling and cause undesirable whiplash. Various approaches in boom design and construction have been employed to achieve greater size and strength without suffering undue weight penalties. The prior art contains numerous examples of prior art telescopic booms.